Pneumatic conveyer



March 23, 1937. `J. E, wooDRUFF I 2,074,527

V- Y PNEUMATIC CONVEYER Filed Nov. so, 1955 INVENTOR Patented Mar. 23, 1937 UNITED STATES PATENT oFFiE PNEUMATIC CONVEYER James Edgar Woodruff, Oakland, Calif. Application November 30, 1935, Serial No. 52,383

2 Claims.

My invention relates generally to pneumatic conveyers of the so-called Lamson type, which are commonly used in stores and the like for inter-departmental dispatching of objects, and

more particularly to the construction of the breeches of such conveyors.

An important object of my invention is to provide an improved latch construction for the breeches of pneumatic conveyers which will elimlo inate to a great extent the inconvenience caused. by the frequent failures of the types of latches now in general use.

Other objects of my invention are to provide a latch construction which will prevent discharge l5 of the dispatch cylinder from the conveyer ree gardless of how worn the heads or the sealing disks thereof may be; to provide an improved latch construction in which the possibilities of the breakage of parts and the entry thereof into 20 the conveyor conduit, where they are likely to cause serious stoppages, are extremely remote; and to provide a latch construction for pneumatic conveyers which, due to its low cost and long life, will effect material savings in the maintenance 25 costs thereof.

Referring to the drawing:

Figure 1 is a front elevation of a conveyer breech showing the latch of my invention mounted thereon.

30 Figure 2 is a vertical sectional View of the structure of Figure 1. The plane of section is indicated by the line 2-2 of the latter ligure.

Figure 3 is a plan view of the device of Figure l; the plane of section being indicated in 35 the latter gure by the line 3 3.

In detail my invention is adapted to be used in conjunction with the so-called Lamson con- Veyer systems. The construction of these systems, and their method of operation, are well 40 known in the art, and therefore should require no introduction, however a brief description thereof will be here given for the benet of those who are not familiar with this type of mechanisrn.

45 Each unit of a system comprises a tubular conduit d having one of its ends 5 opening adjacent a station, which may be, for instance, a particular department in a store, and the other end thereof opening at another station, which may be a dif- 50 ferent department, or, as is usually the case, the

cashiers desk. Each end of the conduit is provided with a bell-mouthed breech casting 6 clamped thereto by means of a screw 1.

A hollow cylindrical object carrier 8 is adapted 55 to be inserted in the conduit 5 at a station and means are provided, usually a blower associated with the conduit, for passing a current of air therethrough, in the right direction, to cause the carrier to be conveyed to the opposite end of the conduit. In order to reduce friction between the 5 carrier and the bore of the conduit, hard rubber heads 9 are provided on each end of the former, and to provide a seal between the carrier and the conduit, so that the maximum force of the air current will act on the carrier, resilient disks i0, 10 usually of soft rubber, are provided on each end thereof.

It will be seen that the carrier, in passing through the conduit, gathers considerable momentum, and in order to prevent discharge there 15 of on to the floor at the receiving station a stop is provided which will bring the carrier to rest at the mouth of the conduit in a position enabling an attendant to readily remove it.

The stop also functions, once a carrier has been started through the conduit toward a receiving station, to prevent discharge of the carrier on to the floor at the station from which it was transmitted should it happen to return thereto, by the action of gravity, in the event that the air current in the conduit should fail, for any reason, during the transmission of the carrier.

The particular type of combination latch and stop mechanism heretofore used in connection with these systems has proven very unsatisfactory. This is due, in a great measure, to the design and method of mounting thereof. The mechanism referred to consists of a spring steel finger which is anchored at one end to the conduit and is bent inwardly so that the other end lies within the conduit in the path of the carrier. The finger is positioned to lie at an angle with the axis of the conduit so that it Will offer little resistance to the passage of the carrier in one direction, being moved aside by the latter in passing, and will prevent passage thereof in the other direction, the end of the finger being positioned so that the approach-end of the carrier will impinge thereon.

It has been found that the finger, due to the solid anchoring of` its fixed end, is severely flexed, duringeaoh passage of a carrier, with the result that, after a short time, the steel crystallizes and the linger breaks thereby necessitating a temporary shut down until replacement of the defeotive part may be effected.

This, however, is the cause of least inconvenience. In the majority of cases the breakage occurs during insertion of a carrier into the conduit and the broken nger is carried thereinto by the carrier, usually to a position a considerable distance from either end whereupon the broken part moves into a position where it wedges between the carrier and the wall of the conduit and causes a stoppage. These stoppages are sometimes so hard to locate and release that the system is out of working order for the better part of a day. rIfhis results in great inconvenience in that the interconnected departments are isolated from each other.

I have provided an improved construction for the latch and stop mechanism, for the type of conveyer system described above, in which the likelihood of the breakage of parts is materially lessened, and in which the chance of broken parts entering the conduit is extremely remote.

The breech casting I3 is provided with a pad Il, on which the end of the former latch nger was secured by means of a screw I2, and on which l mount a. U-shaped bracket I 3 having alined apertures in the sidewalls thereof to receive a cotter pin I4.

I provide a latch finger, to replace that formerly used, which comprises a strip of steel having at one end a groove I5 to provide a pair of tongues i6, formed into loops I'I, which surround the cotter pin I li. The internal diameter of the loops is such that they are freely journaled on the pin.

The strip is provided with an inwardly directed portion I8, which passes through an aperture i9, formed in the side wall of the breech casting 6, and lies at an angle with the axis of the conduit 4, an outwardly directed portion 253, formed as a continuation of the portion I8 and disposed at substantially right angles to the conduit axis, and an upwardly directed portion 2 I, extending from th-e portion 28 and adapted to lie against the side of the casting E. A torsion spring 22 is disposed about the cotter pin I4, in the groove l5, and has one end thereof bearing against the bracket i3 and the other end thereof passing through the groove i5 and hooked so as to engage the outer surface of the portion I 8 of the strip.

It will thus be seen than movement outwardly of the latch finger about a pivot at the axis of the Cotter pin lli, will be resiliently resisted by the spring 22, and that movement inwardly, beyond the position shown in Figure 2, is prevented by the portion 2l of the finger which bears against the casting 6 and provides a stop.

In operation, when a carrier is inserted into the breech casting the leading edge thereof will contact the sloping surface of the portion i8 and will cause the latch finger to swing outwardly about its axis. After passage of the carrier past the latch the latter swings inwardly to the position shown where the flat top surface of the portion 253 projects beyond the inner surface of the breech casting and into the path of the carrier where it will prevent passage thereof outwardly from the conduit. The carrier may be removed from the conduit by manually swinging the finger outwardly whereupon the portions thereof projecting into the conduit will be withdrawn thereby allowing free passage of the carrier.

From the foregoing description it will be seen that I have provided an improved construction for the latch mechanisms of the types of apparatus described, in that no flexure takes place in the latch nger itself thereby eliminating the cause of frequent failure of these parts. The only part of the device which is subject to breakage is the torsion spring 22 which is inexpensive and may be easily and quickly replaced.

The most desirable feature of my improved construction lies in the fact that it is practically impossible for pieces of the latch nger, in the event of breakage thereof, to enter the conduit and cause stoppages.

The most vulnerable point of the latch is the bend 23 and should a fracture occur at this point it will be seen that the upper section of the latch in dropping will be directed outwardly and away from the aperture I9 by the outwardly sloping remaining portion IB. Likewise should the break occur adjacent the pivot of the latch, the entire latch will again, in falling, be directed outwardly and away from the aperture. Thus it is practically irnpossible for pieces of the latch to enter the conduit and cause stoppages which are the cause of the frequent shut-downs inherent in the majority of pneumatic conveyer systems of this type in present use.

I claim:

1. The combination, in a pneumatic conveyer system comprising a conduit through which objects may be dispatched, said conduit having an open end, of a latch disposed adjacent said open end for permitting passage of objects in one direction through said opening and for preventing passage of objects in the other direction through said opening, said latch comprising a pivot mounted externally of said conduit adjacent said opening, a strip of substantially inflexible material having one end journaled on said pivot, a portion directed inwardly into said opening and disposed at an angle with the axis of said conduit, an outwardly directed portion lying at substantially right angles with said axis and a manually engageable portion extending from said con-duit, and means for resiliently urging said strip into said opening.

2. The combination, in a pneumatic conveyer system comprising a conduit through which objects may be dispatched, said conduit having an open end, of a latch disposed adjacent said open end for permitting passage of objects in one direction through said opening and for preventing passage of objects in the other direction through said opening, said latch comprising a U-shaped bracket mounted externally of said conduit adjacent the opening thereof, a pin secured in said bracket, an arm having a slotted end provided with a plurality of loops journaled on said pin, an inwardly directed portion projecting into said opening and lying at an angle with the axis of the conduit, an outwardly directed portion, continuing from said inwardly directed portion, lying at substantially right angles with said axis, a manually engageable portion disposed exterior of said conduit, and a coil spring disposed'in the slotted end of said arm about said pin and having its ends engaging said bracket and said inwardly directed portion of said arm for resiliently urging said arm into said opening.

JAMES EDGAR WOODRUFF. 

